Owning both, I find myself using the kayfun more. I do use the aqua on my origin, but the capacity and slightly wobbly nature of the aqua make it more of an "at home" device for me. If you had to pick just one I'd say you won't be unhappy with your kayfun, stick with that.

I have an original Kayfun V3.1, Kayfun Mini V2.1 and Kayfun Lite... A also used its clones. After Taifun GT, people said that Taifun is better, I've tried an original for a while, I bought a good clone, and yes, it is a very succesfull atomizer. If it is not better it is equal in performance.

And then Aqua.. people says it is better than Kayfun... maybe it is.

But I must admit after a period, still the Kayfun is my favorite, I use it more. Because it is stable, easy, durable, reliable... sometimes simple is the best.

ive had a none ft tobeco un etched for a couple weeks now, far better vape than the kayfuns, yes i have tried the kayfuns, its a drinker especially as a twin coil, mines hybridized onto a ft origen clone, in my humble opinion its better than even the kraken

I prefer my Russian 91% over my Aqua (Tobeco clone).
I can't write a review because I didn't buy it here.
I don't have a Kayfun Lite clone (which I think is the closest thing to the 91%).
So maybe not a perfect comparison.

Aqua:
- Easier to fill (from top - but can be messy if you don't do it just right)
- Juice control (but doesn't really work well - tank gets loose/wobbly when juice control/chimney is no completely closed)- almost useless feature (on Tobeco Clone)
- Drip tip well is wide and short - will not fit most other drip tips
- Low juice capacity
- Single coil build is not optimal due to the air holes placement (2 on the sides - nothing in the middle)
- Dual coils not exactly easy
- Chain vaping sub-ohm - tank/drip tip gets hot
- Will go through juice fast
- Airflow is good - but adjustment is weird since you have to screw in or out the tank - best to find your preferred draw and leave it alone. Tightening compresses liquid in tank causing flooding and leaks.
- Excellent flavor
- 19mm o.d. doesn't fit flush with most mods beside the Origin (looks good on my "naked" DaVapes Poldiac clone though).
- Clear tank available elsewhere (doesn't come with one and cost almost half what the entire atomizer cost me).

2. No view ports so the only way to know you are out of juice is a dry hit (or burnt cotton) or constant opening and checking the juice level.

If I could only have one I would choose a Russian 91% over this or the Kayfun. I prefer a device that has a very long run time between battery changes and juice fills. Still the Aqua is an interesting device and like most devices has a few pros and cons. The Aqua should be great for dual coil sub ohm. Just check the juice every time you change the battery which will be fairly often (during sub ohm use).

"Most people do not really want freedom, because freedom involves responsibility, and most people are frightened of responsibility."

How do these protank's on steroids stack up to a genesis? I usually use gennny's and this will be my first tank of this type. Got it because its 'gonna look fantastic on my origin clone. Looks like the vape might resemble a dual dripper, or, that's my hope. Cant wait (forever lol) to coil it up!